A modified form of bacteria normally present in the vagina may one day be used to protect women from AIDS, according to researchers at Santa Clara, Calif.-based Osel, Inc. The genetically engineered bacteria showed promise in laboratory testing, and researchers now plan to test it in animals. Researchers used a strain of Lactobacillus jensenii, which is generally abundant in mucus secreted by the mucous membrane lining a healthy vagina. The bacteria were modified to produce a protein called CD4, which binds to and inhibits HIV. In laboratory tests the enhanced bacteria reduced the rate of HIV infection in susceptible cells by at least half, the researchers said. Their findings are reported in the online issue of the Proceedings of the National Academy of Sciences.

The research was led by Peter P. Lee of Stanford University, who said in a statement that he envisions the research eventually leading to creation of a small suppository that can be inserted prior to sex to prevent HIV infections. He added that each dose could last a week or longer and could be inserted at any time. He said he hopes to translate the technology to other viruses, such as the human papillomavirus, the herpes virus, and even viruses that cause the common cold or flu.